Radio reproducer



MarchZG, 19291.] w, L, CKHAR 1,706,999;

v RADIO REPRODUCER. v

FileoTJdneil. 1926 2 Shets-Sheet' 1. 1?

2 v LWENTOR.

' M I BY i 30 1 ATTORNEY.

March 26, 1929., w, ECKHARDT I I 1,706,999

I RADIO REPRODUCER Filed June .11. 1926 2 she ts-shet 2 'INV ENTOR.

A T TORNE Y.

Patented Mar. 26, ,1929.

- UNITED sTATEs PATENT OFFICE.

WALTER'L. ECiKHARDT, OF PHILADELPHIA, PENNSYLVANIA.

name nnrnonucnn.

i Application fi1ed June 11,

My invention relates to radio reproducers, and it has for its generalobject to provide a reproducer of novel construction of a character suchthat the tones reproduced thereby are clear, resonant, natural, freefrom blast and without rattle. 1

It is also an object of the invention to pro:

vide a construction of reproducer comprising To theseand other ends theinvention com-- prehends the construction and arrangement of parts ashereinafter described in detail,

of Fig. 4.

ments thereof;

particularly pointed out in the claims and as illustrated in thedrawings in which I have shown certain forms of mechanical embodi- Inthe drawings:

Fig. l is a view in front elevation of a reproducer embodying theinvention Fig. 2 is a View in transverse section taken in a centralvertical plane at right angles to the plane of Fig. 1; r

Fig. 3 is a vertical section of a fragmentary portion of the structureshowing a modifica} tion of the means for securing the vibratorydiaphragm within the drum or cylinder;

Fig. l. is a view in front elevation of a re producer showin aconstruction containing a modified-embodiment of the invention;

and

Fig. 5 is a vertical transverse sect-ional' vie'w taken in a plane atright angles to the plane Referring to the drawings,it will be notedthat the base comprises aportion l of relatively large size and aportion 2 of smaller size secured thereto and centrally thereof and thatto the latter the cylindrical drum shaped member 3 is secured by meansof screws 4 and 5. The member 3 in the construction shown is in the formof a hollow cylinder but may be of other shape in cross section. Itconsists ofwood or of some other material having c0rresponding qualitiesasto amplification, resonan'ce, etc. The member 3 may be describedbroadly as a section of a tube of large trans- 1926. Serial at. 115,159.

verse area. It is provided near its front end portion with an inner band6 also of wood 2 orsimilar material. Located interiorly' of and near thefront end of the tubular resonator 3 is a metal bar 10 which extendsdiametrally of the said resonator. The said bar is provided at itsopposite ends with laterally extended projections 11 constitutingfeetzwhich are seated against the innerside of the lnterior band 6previously referred to.- The said feet are provided with openingsthrough one of which the screw 5, to which previous reference has beenmade, extends. The said screw extends not only through the lower foot 11but also through the band 6 and the resonator 3 into the base of thedevice: The opening through the upper foot 11 is tapped and a screw 12extends through openings in the resonator3 and the band 6 and has screwthreaded engagement with the said tapped opening. The screws 5 and 12operate to secure the circular band (5 in place within the resonator 3and also to secure the vertical metal supporting bar 10 in position.

In addition to the employment of screws 5 and 12 forsecuring theband (5in place cement may be employed, if desired, between the outer surfaceof the said band and the inner opposing portion ofthe surface of theresonator 3 as an additional securing means. The front edge of the band(i may be located a short distance inwardly of the front edge of thetubular resonator-3, as is shown in the'drawmgs, so as to provide acircular groove between the front edge of the band Figs. 2, 3 and 5 ofthe drawings. This band forms. with the inner edgeportion'a grooveforthe reception of a elrcular wire frame 20 upon which is mounted afabric 21 of silk or other suitable material. The inner portion of thesaid fabric is connected to a ring frame portion 22 locatedconcentrically of the tubular resonator 3. "The portions 20,

21 and 22 constitute a closure .forthe rear end.

of the resonator 3. I

In the several forms ofconstruction a diaphragm 23 is provided ofsuitable thin sheet material, such as paper, parchment or the like. Thediaphragm is tapered from a circular line near its outer edge toward therear of the reproducer where it is connected with the rear 'end of'a rod25, commonly called a reed, the front end of which is connected to thevi- 1 bratory element of a loud speaker or reproducer unit 26 mountedupon the metal-bar 10 previously referred to. The usual line wires 27are connected with the said unit. The outer portion of the vibratorydiaphragm terminatesin a rearwardly and laterally extending flange-likeportion 28-.

Referring to Figs. 1 to 3 of the drawings,

it will be noted that the inner edge of the band 6 is tapered from itsinnerside outwardly, as indicated at 30, and that the front side of theouter edge portion of the flange 28 is seated against the surface of thesaid tapered portion.

In the construction as shown in Figs. 1 and 2 of the drawings the outeredge portion of the flange 28 is secured to the inner edge portion ofthe band 6 by means of cement, as indicated at 31. It has been foundthat when the diaphragm is secured to the front edge of the band 6 inthis manner the device operates with entire satisfaction and that thefastening is durable.

In Fig. 3 of-the drawings I have shown a 3 construction in which theouter edge portion ofthe flange 28 is held against the inner edge of theband 6by means of a retaining ring 33 of wood or other suitable materialwhich is fastened in place by means of screws 34 which extend throughthe said ring and through the outer edge portion of the flange 28 intothe band 6.

. In Figs. 4 and 5 of the drawings I have shown a construction in whichthe vibratory 'orbeveled, as indicated at 37. The rearwardly inclinedflange portion 28 of the diaphragm 23 is seated against the rear side ofthe said flange and is secured thereto by cement 38 or by any othersuitable means. The diaphragm supporting frame 35 issecured to the metalbar.10 by means of headed bolts 39 the front ends of which are threadedand are in engagement with tapped openings provided in the bar 10 nearits upper and lower ends.

The only difference between the bar 10 shownin'Figsml and 5 and thecorresponding bar in the preceding figures of the drawingsis that insaid Figs; 4 and 5 the said bar its feet 11 extending toward the frontinstead of the drawings.

It will be noted that the only'essential (life of toward the rear asshown in Figs. 1 and 2 ference between the constructions shown in,

Figs. 1 and2 and 4 and 5 is that in the former the outer peripheralportion of the flange 28 is secured directly to the band 6 and consequently to the drum 3, whereas in the latter Figs. 4 and 5, theperipheral portion of the diaphragm is secured to a frame 35 which inturn is mounted upon the opposite end portions of the diametral bar 10.

It will'be noted that in the construction shown in Figs. 4 and 5 theportion .1 of the base is of somewhat greater length than thecorresponding portion in Figs. 1 and 2 of the drawings. The purpose oflengthening the portion 1 of the base in Figs. 4 and 5 is to permitofthe' mounting of upright posts 40 upon the outer ends thereof theupper ends of which are provided with heads 41 which are located uponthe opposite sides of the tubular resonator 3 1n diametral relation withrespect to each other.

These heads are provided with short projec tions 42 which contact withand are secured to the said resonator for the purpose of constituting anadditional support and steadying means therefor. The posts or columns 40consist of wood or other suitable material.

It may be noted that the rear end of the reed 25 may be connected to thediaphragm 23 at its apex in any known manner.

It also may be noted that the front and rear closures of the tubularresonator 3 may be inserted and'withdrawn at will, the said closuresbeing retained in place by friction of the peripheral surfaces thereofwith the inner frongt and rear edge portions of the resona- While thetubular resonator 3 and the band 6 preferably consist of wood it is tobe understood that these parts may be constructed of any other suitablenon-metal material possessing therequisite qualities of resonance 21ndother characteristics previously referred By the employment of myinvention I am enabled to construct radio reproducers which not only arevery efficient for reproducing sounds having the characteristics andqualitics already indicated, but which also are ornamental inhighdegree.

Having thus described my invention, what I claim and desire to secure byLetters Patent 1s:

material of tubular form and a band secured within one end of the saidsection, a bar extending diametrally of the said resonator and securedthereto at its opposite ends, a reproducer unit mounted on said bar, avibratory diaphragm having operative connection at its outer edge to thesaid band, and a connection between the geometrical center of saiddiaphragm and the said reproducer unit.

2. A radio reproducer, comprising a resonator of wood consisting of ahollow cylindrical member and a band mounted within one end portion ofthe said member, a vibratory diaphragm having a circular portion taperedfrom a circular line near its outer edge to an apex, the portion of thesaid diaphragm be-- yond the said circular line constituting a flange,means for securing said flange to the inner edge of the said band, andmeans having connection with the said diaphragm at its apex foreifectingvibrations thereof.

3. A radio reproducer, comprising in combination a wooden member of drumshape ineluding a band upon the inner-side of one end portion thereof,the inner edge of which is tapered from its inner side outwardly, avibratory diaphragm the outer edge of which is secured to the innertapered edge portion of the said band, a reproducer unit, andaconnection between the said unit and the geometricalcenter of the saiddiaphragm, substantially as described.

4. A radio reproducer, comprising in combination a resonator of drumshape including a band upon the inner side of one end portion thereof,the inner edge of the said band being inclined rearwardly fromits innerside, a vibratory diaphragm located within and extending transversely ofthe said resonator the outer edge of which is mounted upon the inneredge of the said band, means for securing the said diaphragm to the saidband, a bar extending diametrally of the said resonator and secured atits opposite ends thereto, a reproducer unit mounted upon said bar, anda connection between the said unit and the geometrical center of thesaid diaphragm,

substantially as described.

In testimony that I claim'the foregoing as my invention, I have hereuntosigned my

